Subject: [PWE3] A question regarding draft-mohan-pwe3-mpls-eth-oam-iwk-00

From: Alexander Vainshtein <[email-masked]>
Date: Thu, 13 Mar 2008 17:00:15 +0200

Dinesh,
Section 5.1. of the draft describes several options for handing PW
forward defect.
I have two questions regarding this section:

1.	All the options listed in the text require that a (down) MEP
associated with the AC of the PW in question has been configured. Any
ideas what should happen if there is no MEP there?
2.	MEF has ratified the E-LMI IA  as its MEF 16 spec (see
http://metroethernetforum.org/MSWord_Documents/MEF16.doc
<http://metroethernetforum.org/MSWord_Documents/MEF16.doc> ). This
mechanisms seems similar to FR LMI that has been used to convey the FR
PW defects in draft-ietf-pwe3-oam-msg-map-06.txt. Are there any reasons
not to use E-LMI in the same way, at least as one of the options?

Regards,
            Sasha
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From: "Dinesh Mohan" <[email-masked]>
Date: Mon, 17 Mar 2008 23:35:38 -0400

Sasha,
 
Please see inline:
 
--- 
Dinesh 
________________________________

From: Alexander Vainshtein [mailto:[email-masked]] 
Sent: Thursday, March 13, 2008 11:00 AM
To: Mohan, Dinesh (CAR:NP02)
Cc: [email-masked]
Subject: A question regarding draft-mohan-pwe3-mpls-eth-oam-iwk-00

Dinesh,

1.	All the options listed in the text require that a (down) MEP
associated with the AC of the PW in question has been configured. Any
ideas what should happen if there is no MEP there?  DM>> If there is no
MEP, then currently there will be no means to communicate the defect
status to the CE, therefore, there is certainly an assumption made here
that Ethernet OAM must be used at the Ethernet AC for such capabilities.

2.	MEF has ratified the E-LMI IA  as its MEF 16 spec (see
http://metroethernetforum.org/MSWord_Documents/MEF16.doc
<http://metroethernetforum.org/MSWord_Documents/MEF16.doc> ). This
mechanisms seems similar to FR LMI that has been used to convey the FR
PW defects in draft-ietf-pwe3-oam-msg-map-06.txt. Are there any reasons
not to use E-LMI in the same way, at least as one of the options?  DM>>
We can certainly consider adding more options, however, the primary
purpose for deploying E-LMI is provisioning of CE devices and not fault
notifications, therefore the same question arises as to what happens
when E-LMI is not available. The main point here is that the draft
focuses on fault notifications, and for fault purposes, Ethernet OAM is
a basic assumption across AC to keep things simple. 

Regards,
            Sasha